Figure 3
From: Prostaglandin E2 potentiation of P2X3 receptor mediated currents in dorsal root ganglion neurons
EP3 receptors mediate the potentiation of ATP responses by PGE2. (A) In the cell shown, PGE2 increased ATP currents. However, the EP2 receptor-specific agonist, butaprost (Buta) (1 μM), had no effect on the ATP responses. The EP3/EP1 agonist, sulprostone (Sul) (1 μM) mimicked the enhancing effect of PGE2. The EP1 antagonist, SC-19220 (SC) (1 μM), could not block the PGE2 potentiating effect. (B) Bar graphs are the pooled data from 3–8 cells. Only Sul mimicked the PGE2 effect on ATP currents. PGE2 effects: 0.1 μM PGE2, IATP (PGE2)/IATP = 1.22 ± 0.04; 1 μM PGE2, IATP (PGE2)/IATP= 1.49 ± 0.06; 10 μM PGE2, IATP (PGE2)/IATP = 1.76 ± 0.07. Sul effects: 0.1 μM Sul, IATP (Sul)/IATP = 1.25 ± 0.06; 1 μM Sul, IATP (Sul)/IATP = 1.52 ± 0.07; 10 μM Sul, IATP (Sul)/IATP = 1.85 ± 0.08. SC could not inhibit PGE2- or Sul-elicited potentiation. The results suggest that the PGE2 effect is mediated by EP3 receptors. (* P < 0.05, # P < 0.01, NS = not significant)